Start With An Accessible Document; Characteristics Of Accessible Pdf Files - Adobe 09972554AD01A12 - Acrobat Pro - Mac Manual

PDF Accessibility Overview
a PDF file in a systematic fashion. Systematically ruling out or confirming certain characteristics
found in a PDF file will guide the author to the most appropriate path for making an individual
PDF document accessible.

Start with an Accessible Document

The PDF format is a destination file format. PDF files are typically created in some other
application. Optimally document accessibility should begin in the native document format.
For example, many documents are created in a word processing or desktop publishing
application, and then exported as PDF documents. There many things that can be done in
native document applications to support accessibility, such as adding alternative text for
images; defining structural headings, lists, and data tables; providing document language;
and setting document properties such as titles. Adobe desktop publishing applications such
as Adobe InDesign and Framemaker support these features, as well as other word processing
applications such as Microsoft Word. For information on building accessibility into documents
created with Adobe products visit the Adobe Accessibility website. To gain assistance on
adding accessibility into Microsoft Word documents prior to conversion to PDF format please
visit the Microsoft Enable website. Making the native document accessible allows for less work
when changes are made to the native document and the PDF document is regenerated.
If the native document is not available, in most cases, the document can still be made fully
accessible. Without accessibility in the native format there will likely be more manual work
required in the PDF to properly tag the document. There are some items such as choosing
sufficient contrast between foreground and background colors that must be implemented in
the native document.

Characteristics of Accessible PDF files

Accessible PDFs include but are not limited to the following characteristics:
Searchable text
A document that consists of scanned images of text is inherently inaccessible because the
content of the document is a graphic representing the letters on the page, not searchable text.
Assistive technology software cannot read or extract the words in a graphical representation.
Furthermore, users cannot select or edit the text or manipulate the PDF for accessibility.
Scanned images of text must be converted into to searchable text using optical character
recognition (OCR) before addressing accessibility in the document.
Fonts that allow Characters to be Extracted to Text
The fonts in an accessible PDF must contain enough information for Acrobat to correctly extract
all of the characters to text for purposes other than displaying text on the screen. Acrobat
extracts characters to Unicode text when you read a PDF with a screen reader or the Read Out
Loud tool, or when you save as text for a Braille embosser. This extraction fails if Acrobat cannot
determine how to map the font to Unicode characters.
Note: These Best Practices techniques require access to Adobe Acrobat Pro XI for Windows.
Adobe Reader XI and Adobe Acrobat XI Standard do not have the complete set of tools
needed to create and validate PDF documents for accessibility.
Adobe® Acrobat® XI Pro Accessibility Guide: Best Practices for PDF Accessibility
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